Folio3 is a software development partner founded in 2005, focusing on mobile, social media, and enterprise applications with expertise in cloud-based solutions. The document discusses various techniques for implementing HTTP server push, including polling, long polling, and streaming, along with their merits and demerits. It also highlights the role of HTML5 and websockets in improving these traditional methods for more efficient bi-directional communication.

1. HTTP Server PushHTTP Server Push
TechniquesTechniques
www.folio3.com@folio_3

2. Folio3 – OverviewFolio3 – Overview
www.folio3.com @folio_3

3. Who We Are
 We are a Development Partner for our customers
 Design software solutions, not just implement them
 Focus on the solution – Platform and technology agnostic
 Expertise in building applications that are:
Mobile Social Cloud-based Gamified

4. What We Do
 Areas of Focus
 Enterprise
 Custom enterprise applications
 Product development targeting the enterprise
 Mobile
 Custom mobile apps for iOS, Android, Windows Phone, BB OS
 Mobile platform (server-to-server) development
 Social Media
 CMS based websites for consumers and enterprise (corporate, consumer,
community & social networking)
 Social media platform development (enterprise & consumer)

5. Folio3 At a Glance
 Founded in 2005
 Over 200 full time employees
 Offices in the US, Canada, Bulgaria & Pakistan
 Palo Alto, CA.
 Sofia, Bulgaria
 Karachi, Pakistan
Toronto, Canada

6. Areas of Focus: Enterprise
 Automating workflows
 Cloud based solutions
 Application integration
 Platform development
 Healthcare
 Mobile Enterprise
 Digital Media
 Supply Chain

7. Some of Our Enterprise Clients

8. Areas of Focus: Mobile
 Serious enterprise applications for Banks,
Businesses
 Fun consumer apps for app discovery,
interaction, exercise gamification and play
 Educational apps
 Augmented Reality apps
 Mobile Platforms

9. Some of Our Mobile Clients

10. Areas of Focus: Web & Social Media
 Community Sites based on
Content Management Systems
 Enterprise Social Networking
 Social Games for Facebook &
Mobile
 Companion Apps for games

11. Some of Our Web Clients

12. HTTP Server PushHTTP Server Push
TechniquesTechniques
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13. Agenda
 Existing HTTP Protocol Architecture
 Traditional Methods for Server Push
 Polling
 Long Polling / Comet
 Pushlets / Streaming
 Comet in detail
 Possible issues with Comet and their solutions
 Comet Demonstration : MediaMorph
 Where does HTML5 fit-in?
 HTML 5 Server Sockets

14. Existing HTTP Protocol Architecture
 Existing HTTP
 Stateless protocol
 Request – Response … The end !
 Client initiated communication, Always !
 Server is forgetful
 AJAX comes for help

15. Traditional Methods : Polling
 Polling
 Periodic requests by the client
 Time between requests would always be N time units

16. Traditional Methods : Polling
 Merits
 Works better with very high frequency updates
 May suit a very fast / frequent updating system
 Very simple to implement, mostly easiest of all methods
 Works with ancient systems too

17. Traditional Methods : Polling
 De-Merits
 Too much network overhead
 At times slower than expected results
 The updates would always come after N time units
 Possibly too many unnecessary requests
 Possible browser performance degradation on the client
side
 Does not allow cross-domain access

18. Traditional Methods : Long Polling
 Long Polling / Comet
 Client requests and waits for the server to respond
 The server only responds back when there is any update or
data available

19. Traditional Methods : Long Polling
 Merits
 Behaves very similar to what a real server push
mechanism would do
 Immediate response in case of an update from the server
 Comparative to Polling very low network overhead and
request count
 Works with most old and new systems
 Works even with IE 6 !!!

20. Traditional Methods : Long Polling
 De-Merits
 Slightly more complex to implement than polling
 May not work well with very frequent updates
 Needs special server & client configurations
 Needs to take into account the Read Timeout
enforcements by intermediate gateway or proxies
 Does not allow cross-domain access

21. Traditional Methods : Streaming
 Streaming / Pushlet
 One request to the server
 Infinitely long response with continuous messages from
the server
 Client does not talk back unless with a new request
 Javascript <Script> tag enclosed code snippets
 Script tag’s URL would be a comet server side URL.
Sending Javascript code snippets time to time.

22. Traditional Methods : Streaming
 Merits
 Behaves very similar to what a real server push
mechanism would do
 Allows cross-domain implementations, since javascript
urls can be cross-domain
 Immediate response in case of an update from the server
 Possibly very low network overhead
 Negligible request count

23. Traditional Methods : Streaming
 De-Merits
 May not be supported by some old systems
 May cause browser memory overhead because of a long
list of script tags executed on the page
 Client is unable to send new request parameters in
normal scenarios
 All post-event logic needs to be written on the server side
 Proxy servers could buffer responses causing issues

24. Possible issues with Comet and their solutions
 Read timeout
 Orphaned requests
 Very frequent updates – Hybrid Poll – Push.

25. Comet DemonstrationComet Demonstration
www.folio3.com @folio_3

26. Where does HTML5 fit-in?
 HTML5 offers many solutions addressing issues with existing
architectures
 One of the solutions is WebSockets
 WebSockets address almost all issues with the existing
systems

27. HTML5 WebSockets
 HTML5 WebSockets
 Provides bi-directional, full-duplex communications channels
 New URL schems

ws:// - For Plain WebSocket

wss:// - For Secure WebSocket
 Very low network overhead
 Only one request, true full-duplex communication
 Still a long way to go. It is substantial infrastructural change

28. How HTML5 WebSockets Work ?
 Four step lifecycle
 Browser Requests
 Server Responds with Acknowledgement Tokens
 Connection Establishment for Two way communication
 Connection closed by either party

29. Contact
 For more details about our
services, please get in touch with
us.
contact@folio3.com
US Office: (408) 365-4638
www.folio3.com